1. Field of the Invention
The present invention relates to a manufacturing method of an electroluminescent display panel in which a plate or another electroluminescent substrate is laminated over an electroluminescent substrate.
2. Description of Related Art
An electroluminescent (hereinafter referred to as EL) display panel in which two EL substrates are laminated has been known hitherto. One EL substrate emits light of a certain color, and the other EL substrate emits light of a different color, thereby providing a multi-color or full color display when the two substrates are combined as a single unit. One example of the EL display panel of this kind is disclosed in JP-A-64-60993. Two EL substrates, each comprising a pair of electrode layers and a luminescent layer interposed between the pair of electrodes layers, are laminated over each other with a space therebetween. The periphery of the laminated EL substrates is sealed by epoxy resin or a film carrying a connector wiring thereon, thereby forming a single display panel having a space between the two EL substrates which is sealed at its periphery. The peripherally-sealed spacing, (also, termed "closed space" in some references) is brought under vacuum and filled with insulation oil such as silicone oil to protect an active area (an area from which light is emitted) of the EL panel from moisture. To fill the peripherally-sealed spacing with insulation oil, the spacing has to be brought under vacuum, and then the insulation oil has to be introduced. This requires additional manufacturing steps, and moreover there is a possibility that the insulation oil will leak out of the spacing under an extreme environment.
Also, in a single EL display panel which has only one EL substrate and is covered by a cover plate such as a glass plate, a space between the EL substrate and the cover plate has to be filled with insulation oil in the same manner as in the EL panel having two EL substrates. Therefore, the same aforementioned problems are unavoidable.